A computer system includes an identification device and a host. The identification device includes a first wireless module for receiving a radio identification signal and then emitting a radio user signal with an identification code. The host includes a processing module for controlling operation of the host, a second wireless module for emitting the radio identified signal and receiving the user signal, a power supply for supplying power to the processing module while receiving a power control ...

In an electronic article surveillance system, a jamming apparatus is provided for establishing a jamming zone in which tags can be situated and not respond to message signals from a surveillance system transmitter and in which the surveillance system receiver can be situated and still respond to tag signals.

A Code Division Multiple Access (CDMA) communication system which allocates different sets of frequencies to cells with different transmission power levels. Based upon the transmission power levels of a base station for each cell, each base station is assigned to one of at least two groups of base stations. Each group of base stations is assigned a set of frequencies for traffic communication. The set of frequencies assigned to one group of base stations does not overlap with the set of frequenc...

Porous solids having surface area of at least 5 square meters per gram are reduced to smaller particle size by explosive fragmentation. Exemplary disclosure concerns aluminosilicate zeolites in extremely finely divided form prepared by detonation of crystalline zeolites having adsorbed therein explosive compounds and compositions. In one particular embodiment, finely divided zeolite catalyst is supplied to the reactants and energy is furnished to the system by detonation of explosive-loaded crys...

Off premises cable television interdiction apparatus comprises a microprocessor actuation and control means for actuating and controlling one or more frequency agile voltage controlled oscillators. The voltage controlled oscillators selectively jam only unauthorized premium programming transmitted in the clear from a headend to a particular subscriber. Each voltage controlled oscillator is allocated a continuous band of frequencies consistent with the elimination of jamming signal frequency harm...

A communication system comprising a plurality of transceivers each being connected to selected ones of data inputs and at least one unidirectional antenna, each of the transceivers having a first transmitter coupled to the unidirectional antenna transmitting first signals at a first frequency to others of the plurality of transceivers according to a predetermined protocol and a first receiver coupled to the unidirectional antenna receiving second signals at a second frequency from others of the ...

A Code Division Multiple Access (CDMA) communication system which allocates different sets of frequencies to cells with different transmission power levels. Based upon the transmission power levels of a base station for each cell, each base station is assigned to one of at least two groups of base stations. Each group of base stations is assigned a set of frequencies for traffic communication. The set of frequencies assigned to one group of base stations does not overlap with the set of frequenc...

An apparatus for controlling hand-off in a spread-spectrum-CDMA-communications system, for radio devices moving from one cell to another, with each cell having a base station transmitting spread spectrum signals with generic-chip-code signals. A radio device includes a cellular antenna, matched filters, and detectors for detecting generic-chip-code signals embedded in spread-spectrum-communications signals. A comparator generates a comparison signal by comparing the relative time of arrival of a...

The present invention provides a novel burst erasing automatic gain control circuit which includes the basic elements of an automatic gain control circuit and further includes in the loop control circuit, slow response wideband filter means, and a hard limiter which limits the AGC'ed output from the amplifier so that the signal reaching the slow response wideband filter means never exceeds a predetermined value which would cause distortion in the feedback loop. The output of the novel automatic ...

A Television Signal Transmission Security System which provides a higher degree of security then previously possible by utilizing encoding and decoding technology which effectively prevents pirating by amateurs or experimenters. The television signal transmitted is encoded by injecting one or more modulated interfering signals in specific frequency slots in close proximity to the video carrier. Continuous or alternating interfering signals can be injected either above or below the video carrier ...